玉米肽对慢性酒精中毒小鼠认知损伤的 改善作用 Ameliorative effects of corn peptide on cognitive impairment in mice with chronic alcoholism

研究玉米肽对慢性酒精中毒小鼠认知损伤的影响。选取80只ICR小鼠，随机分为 5 组，分别为正常对照组、慢性酒精性脑损伤模型组（酒精模型组）、玉米肽高剂量组（2 g/kg）、玉米肽中剂量组（1 g/kg）、玉米肽低剂量组（0.5 g/kg）。首先进行神经行为学实验（Morris水迷宫实验和避暗实验），然后检测各组小鼠脑组织中多巴胺(DA)、5-羟色胺(5-HT)、γ-氨基丁酸(GABA)含量以及乙酰胆碱酯酶(AChE)、一氧化氮合成酶(NOS)活性，并取大脑海马组织进行病理组织学观察。结果表明：Morris水迷宫实验中，与酒精模型组相比，玉米肽中、高剂量组小鼠的逃避潜伏期显著缩短（P<0.05），有效区域进入次数显著增加（P<0.05），玉米肽中剂量组有效区域运动时间显著延长（P<0.05）；避暗实验表明，玉米肽各剂量组均能显著降低小鼠酒后进入暗箱的错误次数，延长逃避潜伏期（P<0.05）；脑病理组织学显示，玉米肽中、高剂量组能够不同程度地减轻酒精对海马组织的损伤；脑组织中神经递质含量分析发现，玉米肽可调节酒后脑组织中5-HT、DA含量以及NOS的活性，但对酒精导致的AChE活性和GABA含量升高没有下调作用。综上所述，玉米肽可改善小鼠酒后脑组织中部分相关神经递质紊乱导致的细胞和突触功能障碍，从而减轻酒精引起的认知损伤。The effect of corn peptide on cognitive impairment in mice with chronic alcoholism was studied. Eighty ICR mice were randomly divided into five groups: normal control group, chronic alcoholic brain injury model group (alcohol model group), high dosage corn peptide group(2 g/kg), medium dosage corn peptide group(1 g/kg) and low dosage corn peptide group(0.5 g/kg). First, the tests of neurobehavior (Morris water maze and passive avoidance test) were conducted, the levels of dopamine (DA), 5-hydroxytryptamine(5-HT), γ-aminobutyric acid(GABA) and the activities of acetylcholinesterase(AChE) and nitric oxide synthetase (NOS) in brain tissue of mice were detected, and then the brain hippocampal tissue was taken for histopathological observation. The results showed that in the Morris water maze test, compared with the alcohol model group, the escape latency of mice in the midium and high dosage corn peptide groups was significantly shorter and the crossing times significantly increased in the effective area（P<005）; the crossing time in the effective area in the midium dosage corn peptide group significantly increased （P<0.05). The passive avoidance test showed that corn peptide could significantly decrease the number of errors and increase the escape latency (P<0.05). Histopathology showed that midium and high dosage groups of corn peptide could reduce the damage of alcohol to hippocampus in different degree. It was found that corn peptide could modulate the levels of 5-HT, DA and NOS in the brain after drinking, but could not decrease the levels of AChE and GABA induced by alcohol. In conclusion, corn peptide can improve the cellular and synaptic dysfunction caused by the disorder of some related neurotransmitters in the brain tissue of mice after drinking, so as to reduce the cognitive impairment caused by alcohol.